Safety apparatus for an inclined hoist system

ABSTRACT

A safety apparatus for an inclined hoist system of the type having wheeled cars operable on a pair of tracks. A guide mount is mounted on the ties between the tracks and has a guide thereon which includes wooden members extending in the direction of travel of the car and providing lateral flanges. Guide shoes are fixed to and depend from the car and provide flange portions which project under the lateral flanges of the guide. Safety catches depend from the car adjacent the guide shoes and are aligned with continuous surfaces provided by the wooden guide, and a device which is responsive to a runaway condition of the car, is adapted to turn the safety catches into engagement with the wooden surfaces whereby gouging of the wooden members by teeth on the safety catches provides a braking effect. The invention has particular use in shafts with inclines of 20* to 45* for which a satisfactory safety apparatus does not presently exist.

United States Patent [191 Baker Apr. 23, 1974 SAFETY APPARATUS FOR AN INCLINED HOIST SYSTEM [76] lnventorz' Thomas J. Baker, 33 Premier Ave.

W., Kirkland Lake, Ontario, Canada [22] Filed: May 29, 1973 [21] Appl. No.: 364,987

[30] Foreign Application Priority Data Apr. 16, 1973 Canada 168813 [52] U.S. Cl 188/38, 188/126, 188/144 [51] Int. Cl B61k 7/06 [58] Field of Search 188/41-44, 188/63, 125-127, 144, 149, 150.6, 145, 146, 38, 38.5

[56] I References Cited UNITED STATES PATENTS 1,070,360 8/1913 Thompson 188/38 FOREIGN PATENTS OR APPLICATIONS 7,220 3/1901 Great Britain 188/127 Primary Examiner-DuaneA. Reger Attorney, Agent, or Firm-Weir, Marshall, MacRae & Lamb 5 7 ABSTRACT A safety apparatus for an inclined hoist system of the type having wheeled cars operable on a pair of tracks. A guide mount is mounted on the ties between the tracks and has a guide thereon which includes wooden members extending in the direction of travel of the car and providing lateral flanges. Guide shoes are fixed to and depend from the car and provide flangeportions which project under the lateral flanges of the guide. Safety catches depend from the car adjacent the guide shoes and are aligned with continuous surfaces provided by the wooden guide, and a device which is responsive to a runaway condition of the car, is adapted to turn the safety catches into engagement with the wooden surfaces whereby gouging of the wooden members by teeth on the safety catches provides a braking effect. The invention has particular use in shafts with inclines of 20 to 45 for which a satisfactory safety apparatus does not presently exist.

24 Claims, 10 Drawing Figures PATENTEUAPR 23 4974 SPEET 2 BF 3 sh Q EATENTEDAPR23 \974 3.805.923

sum 3 OF 3 SAFETY APPARATUS FOR AN INCLINED HOIST SYSTEM This invention relates to a safety catch, and more particularly to a safety apparatus for an inclined hoist system such as inclined railways used in mines, golf courses and tourist installations.

In railway type conveyances along inclines up to about 5 an ordinary wheel brake may be felt to be satisfactory. In inclined shafts above 60 or 70, the shafts are normally fully timbered, and wooden guides may be readily located adjacent the car and extending in the direction of travel of the car. One arrangement which has proven generally successful in the more steeply disposed shafts utilizes a safety catch which is known as the Ontario safety dog. The Ontario safety dog is provided with a tooth and is incorporated in a system including a spring-loaded arrangement which activates the safety dog to engage a piece of timber and gouge along its length when the tension on the hoisting cable falls below a predetermined value.

In shafts below 60 incline, the shafts are not always timbered, and below 45 incline there is a tendency to use a tunnel structure with no side guides at all. As indicated above, ordinary wheel brakes are commonly used on inclines up to 5. On slopes which include portions with inclines up to about 16 to 20 systems, which have an overspeed governor for actuating a hydraulic arrangement for forcing a brake shoe into functional engagement with the rails, are known. Another similar system utilizes a brake shoe similar to that used on a street car railway wherein the shoe is electromagnetically energized. These types of systems are not effective for inclines greater than that mentioned above because the incline is simply too steep to provide sufficient resistance by way of frictional engagement of a shoe on the track, and moreover, there exists the problem of keeping the car on he track when its downward speed has increased to a value above that of normal travel along the tracks.

Another commonly used system involves a drag bar or dog which ratchets over each tie as the car is pulled in the upwardly direction. In the event, the car is allowedto suddenly descend, such as when a hoisting cable breaks, the dog immediately digs into a tie to hold the car from rolling any farther down the incline. Although -this system has been used on slopes even greater than 20, it is apparent the dog can only be dragged when the car is ascending, it being necessary to pull the dog up when the car is going down. Thus should a cable break when the car is descending or should the dog be inadvertently held up at other times, the car is free to runaway.

Another rather crude arrangement, which has been used but is hardly satisfactory for cars utilized in carrying personnel, is one in which the cars are purposely side-tracked or derailed so as to stop the runaway car by crash impact. With this arrangement an external device has been used to detect a runaway car, the device including a lever which is so disposed near the rails in the shaft that it bumps against each passing car. If a car passes at a high speed the lever bounces sufficient to actuate means for derailing or side-tracking the speeding cars which is possibly destroyed so that additional damage or injury is not caused lower in the shaft.

Other systems which have been used, although not extensively, utilize an extra cable with means for providing a braking force on the cable. In one arrangement the cable passes around a drum carried by the car, the drum being normally allowed to free-wheel but having a device for braking the drum in the case of the car reaching a speed exceeding a predetermined amount. For slopes greater than the unit carried by the car must be so large that it is not practical insofar as weight or initial cost is concerned. In any event, the cable may well be subject to even greater wear than the hoisting cable or rope since it continually passes around the drum, and the cable may well not be reliable in the event the hoisting rope, which may have been subjected to less severe wear, fails and allows the car to start descending at a high speed. A somewhat similar system utilizes a cam arrangement which grabs the cable if a runaway occurs. If the cable has become muddy or greasy, this arrangement may not be reliable and there is the question of whether the cam can properly dissipate the heat produced by the rubbing of the cable over the cam as it grabs the cable. With either of these systems which utilize the extra cable, the cable is subjected to much more severe wear on slopes of smaller incline, of course since it continually drags in the mud, stones and water which accumulate along the bottom of the tunnel.

It may be readily seen from the above that at the present there is not' in use a practical safety apparatus for use in a hoist system operating on an incline of approximately 16 to and particularly in the range of 20 to 45.

As mentioned above, in inclined shafts above 60 to safety dogs, which provide a braking effect by gouging a piece'of wood disposed beside the path of travel of the car, have worked reasonably well. A number of alternatives have been tried, including dogs having a number of teeth arranged more or less in saw tooth fashion. With this type of a dog there appears to be a tendency for the finer teeth to clog and slide over the surface of the wood without any cutting or shearing of the wood taking place. Alternatively if the spacing between the car and wooden member is not consistent the tooth may even tend to be rotated as a gear and thereby assume a position where it provides no braking effect. The above-mentioned Ontario safety dog has prooved generally acceptable in the hoist systems having the steeper incline. However, in cars which travel on rails disposed at 45 or less there is significantly more sloppiness in their travel caused by the noticeable clearance between the rails and wheel flanges and also in the car bearings. Accordingly, use of the Ontario safety dog could result in the hub of the safety dog rubbing against the wooden member or even digging in at some time and being so far away at other times that the tooth would not engage the wooden member if the safety dog was moved to the activated position.

It is an object of the present invention to provide an improved safety apparatus for an inclined hoist system. The invention functions well in shafts inclined at an angle from about 5 to 70, and is particularly useful for inclines of about 20 to 45 for which there is no completely satisfactory system known at the present time.

It is also an object of the present invention to provide a safety catch for use in the above-mentioned system and one which can be utilized with advantage in known systems in shafts of steeper inclines.

According to the present invention, which is a safety apparatus for inclined hoist systems of the type having wheeled cars operable on track means laid on a fixed base means, there is included guide means extending parallel to the track means and a guide mount secured to the base means and projecting upwardly therefrom, the guide means being fixed on the guide mount and having flange means projecting laterally relative to the guide mount. The guide means includes at least one wooden member defining a longitudinal exposed surface. Guide shoe means depend from the car and have a lateral flange portion extending under the flange means of the guide means. A shaft is mounted on the car adjacent the guide shoes and project parallel to the surface of the wooden member, and a safety catch is fixed to the shaft and is aligned with the surface. The safety catch has a tooth for penetration into the wooden member, and means, which are responsive to a runaway condition of the car, is provided for rotating the shaft so as to thereby pivot the safety catch for moving said tooth into contact with the surface of the wooden member.

The relationship between the guide flanges and the guide shoes is such that derailing of the car is prevented, and in addition, by providing the braking force by engaging a portion of the guide means with a toothed safety catch, the co-operation of the guide shoes and guide flanges ensures that the safety catch will always be in a position to engage the wooden member in spite of the tendency for the car to bounce and sway during a runaway condition. Moreover, by forming the flange of the guide means on a guide mount which projects upwardly from the base means, the exposed surface which is engaged by the safety catch, is away from the dirt and small broken rocks which tend to accumulate on the ties between the pair of tracks forming the track means. Accordingly, there is less debris around the surface engaged by the safety catch which could otherwise foul the braking action.

Preferably, the guide means is located substantially midway between the rails or tracks, and the guide means includes a pairof longitudinally extending members forming a pair of opposed flanges, there' being provided means between the wooden members which provides a hoisting cable guide. Thus, the hoisting cable may also be kept from constantly dragging through the water, mud and debris which collects along the top of the ties.

According to the safety catch of the present invention, there is provided a body portion having a platelike configuration defining a forward edge in the direction of pivot of the safety catch into contact with the surface of the wooden member. A hub is formed integrally with the body portion and has a shaft receiving bore with the axis thereof extending normal to the body portion. A tail pad is located on the forward edge and it defines a surface for engagement with the surface of the wooden member for limiting the penetration of the tooth into the wooden member, the engaging surfaces forming a guide contact line. The tooth is formed integrally with the body portion and projects from the forward edge. Between the tooth and the tail pad, a splitter portion is formed on the forward edge of the body portion, the splitter portion being recessed relative to the tooth and the tail pad.

The axis of the hub is located relative to the tooth, splitter gap and tail pad, in a section of an annulus drawn about a reference point F, the annulus having an outer radius R and an inner radius R and being derived from the equation:

R K8,, where K 3.75 for R and K 1.62 for R D, the effective depth of tiietootn'ihairfrom said guide contact line in a direction perpendicular to said guide contact line,

L, length of the splitter gap between the tooth and tail pad measured along a line which is a prolongation of said contact line,

L, effective length of the tail pad measured parallel to said guide contact line.

Preferably, the safety catch also has a tail stop in the form of a projection located past the end of the tail pad opposite the tooth. A stop member is fixed to the car and is arranged for engagement by the tail stop to thereby prevent the pivot of the safety catch in the'direction of pivot a limited amount past a position in -which the tail pad normally engages the surface of the wooden member.

Other features and advantages of the invention will become apparent from the accompanying drawings which illustrate the invention, by way of an example, and wherein:

FIG. 1 is a side view, partially broken for sake of clarity, of a mine car equipped with the safety apparatus of the present invention;

FIG. 2 is a plan view of the mine car in FIG. 1;

FIG. 3 is'an end view of the mine car of FIG. 1;

FIG. 4 is an end view of the guides of an alternative embodiment; 1

FIG. 5 is an end view of the guide of yet another embodiment of the guides;

FIG. 6 is an enlarged top view of the safety catch of the present invention in the engaged position;

FIG. 7 is a front edge view of the safety catch of FIG.

FIG. 8 is a rear view of the tooth tip of the safety catch of FIG. 6;

FIG. 9 is a top view similar to FIG. 6 but showing the safety catch in its normal position; and

FIG. 10 is a view similar to FIG. 6, showing the safety catch moved to a stop engaging position.

' In FIGS. 1 to 3, the reference numeral 20 denotes a wheeled car, which may be a mine car for travel up and down a mine tunnel or shaft 25 on track means 21 in the form of conventional spaced rails or tracks 22. The tracks 22 are secured in spaced parallel relation on fixed base or ties 23 which are layed on the inclined floor 24 of the shaft 25. The car is mounted on flanged wheels 26 which ride on tracks 22, and the car is pulled up the shaft 25 and its descent is controlled by a hoisting rope or cable 27.

Located between tracks 22, 22, and in the preferred embodiment which is illustrated, a guide 30 is centrally disposed and generally extends parallel thereto throughout the length of the incline. The guide 30 includes a guide mount 31 projecting upwardly from the ties and flange means 32 secured along the top thereof. In the embodiment shown in the drawing, the guide is fixed to the ties by lag screws 33. In the embodiment shown in FIGS. 1 to 3 there is provided a pair of parallel guide mounts 31 which are spaced laterally to provide a central trough 34. The guide mounts may consist of metal members or longitudinal extending wooden members as shown in the drawings which are, in the embodiments shown, substantially square timbers. The flange means 31 includes a pair of wooden members which are more rectangular in cross-sections so that when the inside surfaces of the flange means and guide mounts are disposed in flush relationship the flange means provides opposed, laterally projecting flanges 36. The car is provided with a pair of guide shoes 35 at the front and back of the car, the guide shoes projecting beneath the car at the outside of the flanges of the guide means and each having a lateral flange portion 37 extending under the flanges 36 of the guide means 30.

Mounted on the car is a means 40, which is responsive to a runaway condition. The means 40 may be in the form of a speed governor 41 connected by drive means 42 in the form of a chain drive which is driven by one of the wheels 26. In the event the speed of the car exceeds a predetermined amount the means 40 activates a pair of safety catches 43,43 which are located beneath the car immediately adjacent one pair of guide shoes 35. The safety catches are mounted on a pair of depending vertical shafts 44 disposed outside of exposed side surfaces 45 of the flanges 36. Each safety catch 43 is fixed to one of the shafts 44 and aligned with the flange 36 so that when the shaft is turned by the means 40 it engages the surface 45, which, of course extends the length of the guide means. The safety catch 43 has a tooth 46 which is generally pointed in the direction of descent of the car so that as the safety catch is pivoted toengage the-surface 45, the tooth gouges or chisels wood from thewooden member forming the flange of the guide means so as to thereby dissipate energy and bring the car to a stop. The safety catch will be described in more detail below, but it may be noted that the safety catch further has a tail pad 47 which also engages the surface 45 of the guide flange to limit the penetration of the tooth into the wooden member.

It is believed apparent from the above that regardless of the motion which a car might normally experience during excessive speed in a runaway condition, because of the co-operation between flanges 36 of the guide means and flange portions 37 of the guide shoes, the car cannot derail, and of equal importance, the motion of the car is restricted to the extent that the safety catches are held immediately adjacent the surfaces 45. Thus, once the safety catches have been actuated, they must engage the surface 45 and remain in engagement until the car is brought to a safe stop. Moreover, since the flange means 32 are mounted on top of guide mounts 31 the wooden member forming the flange means, and particularly surface 45, is disposed well above the stone chips, mud and other debris which normally collects along the floor 24 of the shaft.

In the embodiment shown in FIGS. 1 to 3, the hoisting cable may also be guided in the control space or trough 34 provided between the longitudinally extending pair of wooden members, and it is possible to provide rollers 50 which are mounted for rotation on transverse shafts 51 which span the trough 34. The rollers may be formed with a concave groove for accomodating the cable and which tend to keep the cable centrally disposed in the trough. Such an arrangment maintains the cable well above the ties and debris and water which has collected between the tracks.

In the embodiment of the guide means shown in FIG. 4, there is again provided a pair of spaced guide mounts in the form of longitudinal wooden members 52 which are secured to the top of ties 23. Another pair of wooden members 53, which may be of the same width as wooden members 52 are secured on the top of the guide mounts. Secured to the outer side surfaces 54 of the wooden members 53 are longitudinally extending angle irons 55. Each angle iron 55 have one leg secured to the side surface 54 of one member 53, and the other leg thereof projects laterally so that opposed laterally projecting flanges are provided along the length of the guide means for co-operating with guide shoes 35 as described above. The wooden members 53 thus have exposed top surfaces 56 which perform the same function of side surfaces 45 in the above-described embodiment. The safety catches 43, 43 are therefore mounted on horizontal shafts 57 which are rotated by the speed responsive means 40 so as to turn the safety catches down into engagement with exposed top surface of the wooden members. As in the previously described embodiment the wooden members are spaced to provide a guide for the hoisting cable and again rollers may be provided in the space for carrying the weight of the cable.

The arrangement shown in FIG. 5 is more suitable with tracks of narrow gauge and includes a single guide mount 60 located midway between the tracks and extending along the length thereof. A pair of wooden members 61,61 having a total width greater than that of the guide mount 60 is secured on top of the guide mount so as to project laterally from opposite sides of the guide mount and provide side flanges 62,62. A pair of guide shoes (not shown) co-operate with the side flanges in the manner described above, and safety catches (not shown) may be arranged to either engage the top exposed surfaces 63, 63 or side surfaces 64,64. Although this embodiment does not provide a large central space in which rollers may be mounted to carry the hoisting cable, the inner upper corners of wooden members 61, 61 may be bevelled as at 65'so as to provide a longitudinally extending V-shaped groove 66 in the upper surface of the guide means, which groove may act as a guide for the hoisting cable.

Referring now to FIGS. 6 to 10, it may be noted that the safety catch 43 has a plate-like configuration defining a forward edge in the direction of pivot of the safety catch into contact with surface 45 of the guide means, the tooth 46 projecting from thisforward edge. As shown, tail pad 47 is arranged on the same forward edge of the safety catch and ahead of the tooth in the direction of travel of the car down an incline, the tooth 46 and tail pad 47 being separated by a splitter portion 70 which is recessed relative to the tail pad. A hub 71 is formed integrally with the body portion and has a shaft receiving bore 72 for reception of the shaft 44 of the embodiment shown in FIGS. 1 to 3. The bore includes a keyway 73 in order that the safety catch is fixed for rotation with the shaft.

In relation to the tooth 46 and the tail pad, the axis 74 of the hub is located with within a section of an annulus shown as f f f f, in FIG. 6. The annulus f f f f is drawn about a reference point F and is contained between outer radius R and inner radius R, wherein R is derived by the following equation:

R KB where K 3.75 for R and K 1.62 sfor R d t L30 pr) When in the engaged position, i.e., the tail pad bears against surface 45 of the wooden member, surface 76 of the tail pad and surface 45 against which it engages form that which is herein described as a guide contact line. D, represents the effective depth of the tooth measured from the guide contact line in a direction perpendicular to the guide contact line. If the tooth has a flat tip, D, is the distance from the guide contact line to the tooth tip, and if the tip is pointed, as is illustrated in the drawings and is more fully described below, the effective depth is measured from the guide contact line to a point centrally disposed in the V-shaped point.

The splitter gap portion has a length L and this is measured along a prolongation of the guide contact line and is thedistance between the tooth and the tail pad.

The length of the tail pad is a distance measured parallel to the guide contact line, and in the preferred embodiment wherein the tail pad includes a curved portion 77 which curves away from the guide contact line, the effective length L,,, of the tail pad is taken as being the distance of flat contact of the tail pad along the guide contact line plus an additional distance to a line drawn perpendicular to the guide contact line and through a point which is a distance of l 10 L from the guide contact line.

The reference point F is located at the intersection of a line drawn perpendicular to the guide contact line through the midpoint of the measurement L,,, and a line drawn parallel to theguide contact line through the midpoint of the measurement D The radial lines which form the sides of the annulus are drawn from the point F at angles of 14 and 46 relative to the guide contact line. The optimum location of the axis of the hub appears to be at a point when it is located on a radius derived from the equation:

R KB where K 1.41, and on a radial line drawn from the reference point at an angle of approximately 25 relative to the guide contact line. It is also believed that better results are obtained when L,-, is not less than 1.5 D,, and preferably L substantially equals 2.0 D,.

As indicated above, the tip of the tooth is preferably pointed, and the point is provided by making a pair of bevel surfaces 80,80 on the rear 1 edge of the tooth which bevels intersect on the front surface of the tooth, the common ridge 81 of the bevels 80,80 extending to the apex of the V-shaped tip. In this arrangement, which is best illustrated in FIG. 8, a tooth bite angle M may be selected, this angle being that measured between either one of the pair of bevel surfaces and a line parallel to the axis 74 of the bore, the angle being measured in a plane which is normal to the guide contact line and parallel to the axis 74. The tooth bite angle M falls in the range of 10 to 60. The angle M is preferable in the range of to 40, and best results are believed obtainable when the angle is approximately although the optimum angle varies somewhat with the width of the tooth which has been selected.

As indicated above, the tail pad 47 has a curved portion 77, the curved portion 77 curves smoothly into the flat portion of the tail pad 47 at one end and terminates at its opposite end at a tail stop 83 which is in the form of a projection on the end of the body portion of the safety catch opposite to the hub 71. Depending from the car 20 is a bar or a stop member 84 against which the tail stop 83 engages to limit the pivot of the safety catch in the actuated direction. The curved portion 77 causes the safety catch to ride smoothly over any irregularities which may occur along the surface 45, and thereby prevents jumping and jamming of the safety catch. In the event a portion of the member is missing or is badly damaged so that the safety catch turns in excessively when activated, its movement is limited by the engagement of the tail stop 83 with the stop member 84. Thus as the safety catch approaches the normal surface 45, the safety catch rides back to its normal position as the curved portion 77 follows the surface of the wooden member. Moreover, the above described features of the invention make the present invention particularly well adapted for use in systems which have switch locations. When used in a shaft having a shallow incline, it may be desirable to run cars from the inclined shafts out into level tunnels. This can be done by lowering a drawbridge from the level tunnel into the inclined shaft. With such an arrangement it is necessary to provide a rather long gap in the guide means in order that the car can leave the tracks of the inclined shaft. Without the tail stop 83 and stop member 84, the safety catch on a runaway car could turn completely in as the car passed over the gap. Accordingly, even after the car passes the gap the safety catches would not be in a position to properly engage the surface 45 and provide a braking effect. In fact the safety catches could turn to a position in which they are simply destroyed when they smash into the guide means which commences at the lower end of the switching gap. In the presentinvention, the wooden members which form flanges 36, are tapered at the ends immediately below a switching gap as illustrated in FIGS. 2 and 10 so as to provide a tapered surface 45a which eventually merges into surface 45.

In the event a car experiences a runaway condition the safety catch will be activated and therefore turns from the position shown in FIG. 9 to that shown in FIG. 6; If the safety catch is activated as the car is passing a switching gap or passes the gap after the safety catches are activated, the safety catch will be turned until it reaches the position shown in FIG. 10 with the tail stop 83 engaging the stop member 84. As the safety catch then approaches the guide means 30 below the switch gap the curved portion 77 of the tail pad rides along the tapered surface 45a to thereby return the safety catch from the position shown in FIG. 10 to that shown in FIG. 6 so that normal braking is continued.

As explained above, the tooth 46 gouges out a continuous section of wood. The shape of the tooth encourages further penetration once the gouging has commenced but the amount of penetration is limited by the engagement of the tail pad 47 with the surface 45 of the wooden member. Energy is thus absorbed by the destruction of the wood by the tooth 46 and the subsequent splitting of the gouged section by the splitter portion 70, which is in the form of a sharp edge.

The particular relationship of the various portions of the safety catch result in rapid initial penetration with a relatively low pressure being applied by the shaft 44. The use of the pointed tip on the tooth 46 also concentrates the pressure pushing the tooth 46 against the surface 45 so that guicker penetration is achieved.

Moreover the particular design of the safety catch of the present invention provides for good clearance between the hub 71 and the surface 45 so that sloppiness in travel of the car along the tracks does not result in the wearing of the hub against the guide means, or accidental engagement of the tooth with the surface 45. Alternatively, when the car sways in the opposite direction, so that the distance between the hub and guide means becomes excess, proper penetration of the tooth will be achieved if the safety catch is engaged, and there is no danger of the safety catch being rotated too far or even wrenched through to an inoperative posi tion.

Although the novel safety catch has been described in a safety apparatus which is particularly useful in a system which is inclined less than 60, it is believed apparent that the same safety catch could be utilized in place of known units, such as the Ontario safety dog, and would be particularly advantageous in steep shafts where there exists guides which are rather severly worn or deteriorated in strength.

Preferred embodiments of the invention have been described, but it may be readily apparent to those skilled in the art that various modifications are possible without departing from the spirit of the invention as defined in the appending claims.

I claim:

1. A safety apparatus for an inclined hoist system of the type having wheeled cars operable on track means laid on a fixed base means, the apparatus comprising: guide means extending parallel to the track means, a guide mount secured to the base means and projecting upwardly therefrom, said guide means being fixed on the guide mount and having flange means projecting laterally relative to the guide mount, said guide means including at least one wooden member defining a longitudinal exposed surface, guide shoe means depending from the car and having a lateral flange portion extending under the flange means of said guide means, a shaft mounted on said car adjacent said guide shoes and projecting parallel to said surface of said wooden member, a safety catch fixed to said shaft and aligned with said surface, said safety catch having a tooth for penetration into said wooden member, and means responsive to a runaway condition of said car for rotating said shaft and to thereby pivot said safety catch for moving said tooth into contact with said surface.

2. An apparatus as defined in claim 1, wherein said flange means includes a pair of opposed flanges projecting laterally relative to the guide mount, and said guide shoe means includes a pair of guide shoes each having a lateral flange portion extending one each under said flanges of said guide means.

3. An apparatus as defined in claim 2, wherein said track means includes a pair of tracks and said guide means is located substantially midway between said tracks, said guide means including a pair of longitudinally extending wooden members, means being provided between said wooden members forming a hoisting cable guide.

4. An apparatus as defined in claim 3, wherein said wooden members are arranged in spaced parallel relationship, roller members being mounted between said wooden members to provide said hoisting cable guide.

5. An apparatus as defined in claim 2 wherein said guide mount includes a pair of longitudinally extending wooden members, the wooden members forming said guide members being secured on said guide mount and being of greater width than the wooden members forming the guide mount so as to form the laterally projecting flanges.

6. An apparatus as defined in claim 2, wherein the guide means includes a pair of wooden members, said wooden members defining said opposed flanges and each having an outer exposed side surface, a pair of said shafts being provided one each of said shafts depending from said car outside of each side surface, one of said safety catches being fixed to each shaft and aligned with the side surface of the wooden member adjacent thereto.

7. An apparatus as defined in claim 2, wherein said guide means includes a pair of wooden members each having an exposed upper surface, said shaft being horizontally disposed and having a pair of the safety catches mounted thereon in alignment one each with the upper surfaces of said pair of wooden members.

8. An apparatus as defined in claim 7, wherein said pair of wooden members each define an outer side surface, and wherein each of said opposed flanges are formed by an angle iron fixed to the side surface of one of said wooden members, the angle iron having the leg thereof secured to the wooden member with the other leg thereof projecting laterally from the side surface.

9. An apparatus as defined in claim 1, wherein the means responsive to a runaway condition is a speed governor means.

10. An apparatus as defined in claim 1, wherein said safety catch comprises a body portion having a platelike configuration defining a forward edge in the direction of pivot of said safety catch into contact with said surface, a hub formed integrally with said body portion and having a shaft receiving bore with the axis thereof extending normal to said body portion, a tail pad on said forward edge and defining a surface for engagement with said surface of said wooden member for thereby limiting the penetration of said tooth into said wooden member, said engaging surfaces forming a guide contact line, said tooth being formed integrally with said body portion and projecting from said forward edge at a location between said tail pad and said hub, said body portion having a splitter portion formed on said forward edge between said tooth and said tail pad, said splitter portion being within a splitter gap and being recessed relative to said tooth and tail pad, the axis of said hub being located, relative to the tooth, splitter gap and tail pad, in a section of an annulus drawn about a reference point F, the annulus having an outer radius R and an inner radius R and being derived from the equation:

R KB where K 3.75 for R and K 1.62 for R 8,, v. D, L L,,,.), where D, the effective depth of the tooth measured from said guide contact line in a direction perpendicular to said guide contact line.

L length of the splitter gap between the tooth and tail pad and measured along a line which is a prolongation of said guide contact line,

L,,, effective length of the tail pad measured parallel to said guide contact line,

the reference point F being located at an intersection of a line drawn normal to the guide contact line from the midpoint L, and a line drawn parallel to the guide contact line from the midpoint of D,, the sides of the section being defined by radial lines drawn from reference point F at angles of 14 and 46 relative to the guide contact line.

11. An apparatus as defined in claim 10, wherein said safety catch further comprises a tail stop in the form of a projection located past an end of said tail pad opposite said tooth, and further comprising a stop member fixed to said car and arranged for engagement by said tail stop to thereby prevent the pivot of said safety catch in said direction of pivot a limited amount past a position in which said tail pad normally engages said surface of said wooden member.

12. A safety catch for use in a hoist system of the type having a car drawn upwardly along a path of guided travel, a wooden member extending'parallel to said path adjacent the car, said wooden member defining a longitudinal surface for engagement by said safety catch during uncontrolled descent of the car along said path; said safety catch comprising a body portion, a hub portion formed integrally with and located at one end of said body portion, said hub portion having a shaft receiving bore with the axis thereof extending normal to said body portion, said body portion projecting away from said hub portion in the direction of descent and defining a forward edge in the direction of pivot of said safety catch about said axis in a direction toward said surface of said wooden member, a tooth on said forward edge, a tail pad on said forward edge and defining a surface for engagement with said surface of said wooden member for thereby limiting the penetration of said tooth into said wooden member, said engaging surfaces forming a guide contact line, said tooth being formed integrally with said body portion and protruding from said forward edge at a location between said tail pad and said hub, said tooth defining a gouging surface on a front side thereof relative to the direction of descent, the front surface being disposed at an angle relative to the line of contact and extending from a tip of said tooth in a rearwardly inclined relation relative to the direction of descent, said body portion having a splitter portion formed on said forward edge between the gouging surface of the tooth and said tail pad, said splitter portion being within a splitter gap and being recessed relative to said tooth and tail pad, the axis of said hub being located, relative to the tooth, splitter gap and tail pad, in a section of an annulus drawn about a reference point F, the annulus having an outer radius R, and an inner radius R and being derived from the equation:

R KB where K 3.75 for R and K 1.62 for R 8,, 1% D, L L where D, the effective depth of the tooth measured from said guide contact line in a direction perpendicular to said guide contactline,

L length of the splitter gap between the tooth and tail pad measured along a line which is a prolongation of said contact line,

L,,, effective length of the tail pad measured parallel to said guide contact line,

the reference point F being located at an intersection of a line drawn normal to the guide contact line from the midpoint of L and a line drawn parallel to the guide contact line from the midpoint of D the sides of the section being defined by radial lines drawn from reference point F at angles of 14 and 46 relative to the guide contact line.

13. A safety catch as defined in claim 12, wherein L is not less than 1.5 D

7 14. A safety catch as defined in claim 12 wherein L substantially equals 2.0 D,.

15. A safety catch as defined in claim 12, wherein said surface of said tail pad includes a planar surface and a curved surface extending away from said contact line, the curved surface merging. smoothly with said planar surface at the end of the planar surface opposite to said splitter gap, and wherein L, is a distance measured along the planar surface from the splitter gap and a distance past the opposite end of the planar surface to a point on said contact line which is on a line drawn perpendicular to the contact line and through a point of said curved surface which is a distance of 1/10 L from said contact line and measured perpendicular thereto.

16. A safety catch as defined in claim 15, wherein said curved surface terminates at a tail stop formed integrally with said body portion.

17. A safety catch as defined in claim 12, wherein the axis of the hub portion is located on a radius derived from said equation:

R KB where 18. A safety catch as defined in claim 12 wherein the axis of the hub is located on a radial line drawn from the reference point at an angle of 25 relative to the guide contact line.

19. A safety catch as defined in claim 12, wherein said tip of said tooth is a V-shaped portion, the tooth having a bevelled surface intersecting the front surface to define said tip, the bevelled surface comprising a pair of surfaces having a common ridge line extending into the apex of the V-shaped tip.

20. a safety catch as defined in claim 19, having a tooth bite angle in the range of 10 to 60, the tooth bite angle being the angle measured between either of said pair of surfaces and a line parallel to the axis of the bore in said nub, the angle being measured in a plane which is normal to the guide contact line and parallel to said axis of the bore.

21. A safety catch as defined in claim 20 wherein said bit angle is in the range of 20 to 40.

22. A safety catch as defined in claim 20 wherein said bit angle is approximately 25.

23. A safety catch as defined in claim 19, wherein D, is measured from said guide contact line to a point centrally disposed in said V-shaped portion.

24. A safety catch as defined in claim 12, wherein said splitter portion is in the form of a sharp edge. 

1. A safety apparatus for an inclined hoist system of the type having wheeled cars operable on track means laid on a fixed base means, the apparatus comprising: guide means extending parallel to the track means, a guide mount secured to the base means and projecting upwardly therefrom, said guide means being fixed on the guide mount and having flange means projecting laterally relative to the guide mount, said guide means including at least one wooden member defining a longitudinal exposed surface, guide shoe means depending from the car and having a lateral flange portion extending under the flange means of said guide means, a shaft mounted on said car adjacent said guide shoes and projecting parallel to said surface of said wooden member, a safety catch fixed to said shaft and aligned with said surface, said safety catch having a tooth for penetration into said wooden member, and means responsive to a runaway condition of said car for rotating said shaft and to thereby pivot said safety catch for moving said tooth into contact with said surface.
 2. An apparatus as defined in cLaim 1, wherein said flange means includes a pair of opposed flanges projecting laterally relative to the guide mount, and said guide shoe means includes a pair of guide shoes each having a lateral flange portion extending one each under said flanges of said guide means.
 3. An apparatus as defined in claim 2, wherein said track means includes a pair of tracks and said guide means is located substantially midway between said tracks, said guide means including a pair of longitudinally extending wooden members, means being provided between said wooden members forming a hoisting cable guide.
 4. An apparatus as defined in claim 3, wherein said wooden members are arranged in spaced parallel relationship, roller members being mounted between said wooden members to provide said hoisting cable guide.
 5. An apparatus as defined in claim 2 wherein said guide mount includes a pair of longitudinally extending wooden members, the wooden members forming said guide members being secured on said guide mount and being of greater width than the wooden members forming the guide mount so as to form the laterally projecting flanges.
 6. An apparatus as defined in claim 2, wherein the guide means includes a pair of wooden members, said wooden members defining said opposed flanges and each having an outer exposed side surface, a pair of said shafts being provided one each of said shafts depending from said car outside of each side surface, =one of said safety catches being fixed to each shaft and aligned with the side surface of the wooden member adjacent thereto.
 7. An apparatus as defined in claim 2, wherein said guide means includes a pair of wooden members each having an exposed upper surface, said shaft being horizontally disposed and having a pair of the safety catches mounted thereon in alignment one each with the upper surfaces of said pair of wooden members.
 8. An apparatus as defined in claim 7, wherein said pair of wooden members each define an outer side surface, and wherein each of said opposed flanges are formed by an angle iron fixed to the side surface of one of said wooden members, the angle iron having the leg thereof secured to the wooden member with the other leg thereof projecting laterally from the side surface.
 9. An apparatus as defined in claim 1, wherein the means responsive to a runaway condition is a speed governor means.
 10. An apparatus as defined in claim 1, wherein said safety catch comprises a body portion having a plate-like configuration defining a forward edge in the direction of pivot of said safety catch into contact with said surface, a hub formed integrally with said body portion and having a shaft receiving bore with the axis thereof extending normal to said body portion, a tail pad on said forward edge and defining a surface for engagement with said surface of said wooden member for thereby limiting the penetration of said tooth into said wooden member, said engaging surfaces forming a guide contact line, said tooth being formed integrally with said body portion and projecting from said forward edge at a location between said tail pad and said hub, said body portion having a splitter portion formed on said forward edge between said tooth and said tail pad, said splitter portion being within a splitter gap and being recessed relative to said tooth and tail pad, the axis of said hub being located, relative to the tooth, splitter gap and tail pad, in a section of an annulus drawn about a reference point F, the annulus having an outer radius R1 and an inner radius R2 and being derived from the equation: R KBd where K 3.75 for R1 and K 1.62 for R2, Bd ( 1/2 Dt + Lsg + Lpr), where Dt the effective depth of the tooth measured from said guide contact line in a direction perpendicular to said guide contact line. Lsg length of tHe splitter gap between the tooth and tail pad and measured along a line which is a prolongation of said guide contact line, Lpr effective length of the tail pad measured parallel to said guide contact line, the reference point F being located at an intersection of a line drawn normal to the guide contact line from the midpoint Lpr and a line drawn parallel to the guide contact line from the midpoint of Dt, the sides of the section being defined by radial lines drawn from reference point F at angles of 14* and 46* relative to the guide contact line.
 11. An apparatus as defined in claim 10, wherein said safety catch further comprises a tail stop in the form of a projection located past an end of said tail pad opposite said tooth, and further comprising a stop member fixed to said car and arranged for engagement by said tail stop to thereby prevent the pivot of said safety catch in said direction of pivot a limited amount past a position in which said tail pad normally engages said surface of said wooden member.
 12. A safety catch for use in a hoist system of the type having a car drawn upwardly along a path of guided travel, a wooden member extending parallel to said path adjacent the car, said wooden member defining a longitudinal surface for engagement by said safety catch during uncontrolled descent of the car along said path; said safety catch comprising a body portion, a hub portion formed integrally with and located at one end of said body portion, said hub portion having a shaft receiving bore with the axis thereof extending normal to said body portion, said body portion projecting away from said hub portion in the direction of descent and defining a forward edge in the direction of pivot of said safety catch about said axis in a direction toward said surface of said wooden member, a tooth on said forward edge, a tail pad on said forward edge and defining a surface for engagement with said surface of said wooden member for thereby limiting the penetration of said tooth into said wooden member, said engaging surfaces forming a guide contact line, said tooth being formed integrally with said body portion and protruding from said forward edge at a location between said tail pad and said hub, said tooth defining a gouging surface on a front side thereof relative to the direction of descent, the front surface being disposed at an angle relative to the line of contact and extending from a tip of said tooth in a rearwardly inclined relation relative to the direction of descent, said body portion having a splitter portion formed on said forward edge between the gouging surface of the tooth and said tail pad, said splitter portion being within a splitter gap and being recessed relative to said tooth and tail pad, the axis of said hub being located, relative to the tooth, splitter gap and tail pad, in a section of an annulus drawn about a reference point F, the annulus having an outer radius R1 and an inner radius R2 and being derived from the equation: R KBd where K 3.75 for R1 and K 1.62 for R2, Bd ( 1/2 Dt + Lsg + Lpr), where Dt the effective depth of the tooth measured from said guide contact line in a direction perpendicular to said guide contact line, Lsg length of the splitter gap between the tooth and tail pad measured along a line which is a prolongation of said contact line, Lpr effective length of the tail pad measured parallel to said guide contact line, the reference point F being located at an intersection of a line drawn normal to the guide contact line from the midpoint of Lpr and a line drawn parallel to the guide contact line from the midpoint of Dt, the sides of the section being defined by radial lines drawn from refeRence point F at angles of 14* and 46* relative to the guide contact line.
 13. A safety catch as defined in claim 12, wherein Lsg is not less than 1.5 Dt.
 14. A safety catch as defined in claim 12 wherein Lsg substantially equals 2.0 Dt.
 15. A safety catch as defined in claim 12, wherein said surface of said tail pad includes a planar surface and a curved surface extending away from said contact line, the curved surface merging smoothly with said planar surface at the end of the planar surface opposite to said splitter gap, and wherein Lpr is a distance measured along the planar surface from the splitter gap and a distance past the opposite end of the planar surface to a point on said contact line which is on a line drawn perpendicular to the contact line and through a point of said curved surface which is a distance of 1/10 Lpr from said contact line and measured perpendicular thereto.
 16. A safety catch as defined in claim 15, wherein said curved surface terminates at a tail stop formed integrally with said body portion.
 17. A safety catch as defined in claim 12, wherein the axis of the hub portion is located on a radius derived from said equation: R KBd where K 1.41
 18. A safety catch as defined in claim 12 wherein the axis of the hub is located on a radial line drawn from the reference point at an angle of 25* relative to the guide contact line.
 19. A safety catch as defined in claim 12, wherein said tip of said tooth is a V-shaped portion, the tooth having a bevelled surface intersecting the front surface to define said tip, the bevelled surface comprising a pair of surfaces having a common ridge line extending into the apex of the V-shaped tip.
 20. a safety catch as defined in claim 19, having a tooth bite angle in the range of 10* to 60*, the tooth bite angle being the angle measured between either of said pair of surfaces and a line parallel to the axis of the bore in said nub, the angle being measured in a plane which is normal to the guide contact line and parallel to said axis of the bore.
 21. A safety catch as defined in claim 20 wherein said bit angle is in the range of 20* to 40*.
 22. A safety catch as defined in claim 20 wherein said bit angle is approximately 25*.
 23. A safety catch as defined in claim 19, wherein Dt is measured from said guide contact line to a point centrally disposed in said V-shaped portion.
 24. A safety catch as defined in claim 12, wherein said splitter portion is in the form of a sharp edge. 